Did you get an answer to your question regarding Hoya's? I'm a bit late in seeing this but I grow a couple of Hoyas and will try to help if I can. We don't have a Hoya forum here on ATP but there is one at Cubits with some very knowledgeable growers. There have been threads here at ATP pertaining to Hoya (I think on the Houseplant Forum) and I know of one extremely knowledgeable and helpful person here who I'm sure could answer any question you might have about these wonderful plants!